Retainer plate for a pump



FIG. 1 is a top front perspective view of a retainer plate for a pump showing my new design, with the bottom rear perspective view being identical thereto.

FIG. 2 is a top plan view thereof, with the bottom plan view being identical thereto; and,

FIG. 3 is a front elevation view thereof, with the back elevation view, the left side elevation view, and the right side elevation view being identical thereto.

The dash-dash broken lines shown in the drawings illustrate portions of the retainer plate that form no part of the claimed design. 

CLAIM The ornamental design for a retainer plate for a pump, as shown and described. 